So I Had A Thought For A Engine Swap

[benjy_26]

funny you say that because my buddy is scrapping his mr2 and he has a fresh rebuilt 3sgte with 0 miles on it sitting in his garage with no plans for it that I know of.

 

 

BTW where are you located in Tx if you don't mind me asking.

I'm in a top secret, underground, government installation.... J/K I'm i El Paso.

 

If you can snaggle that 3S, DO IT. 200HP, 200ftlbs in stock trim is what that thing brings to the party. As much as I love me some Jeep L6 goodness, I dare anyone to show me a CL-special 4.0 that'll throw those #'s down. Add a free flowing exhaust, intake, and some fuel and ignition tuning ane you're good for 240. Slap on a slightly bigger turbo, and 300 very reliable HP is not out of the question.

[benjy_26]

BTW, a FULLY dressed 3SGTE is weighing in at around 450lbs. The 4.0 is supposed to weigh in at around 480. Don't know if that's dressed or not.

[mnkyboy]

3s gte 210 PS (154 kW; 207 hp) at 7,600 rpm and 22.0 kg·m (216 N·m) at 6,400 rpm.

 

Looking at those numbers a stock 4.0l will have no trouble out pulling it.

[benjy_26]

Stock to stock, yes. I have a pretty healthy 4.6l stroker and I am no where near getting 300hp. A 3SGTE can get that easily.

[mnkyboy]

Problem is the rpm. It takes the Toyota engine 7000rpm to do what a 4.0l does a little off idle.

[HOrnbrod]

Stock to stock, yes. I have a pretty healthy 4.6l stroker and I am no where near getting 300hp. A 3SGTE can get that easily.

 

How do you know? Ever have it dynoed?

 

http://www.jeepstrokers.com/forum/viewtopic.php?f=5&t=387

 

And it's better than that now. 

[benjy_26]

Yup. I'm hitting a bit over 260whpon the dyno pushing 32's and a 42re. My 3S puts out a respectable 346whp. All of this is at 3000ft above sea level on a Mustang chassis dyno.

[benjy_26]

Problem is the rpm. It takes the Toyota engine 7000rpm to do what a 4.0l does a little off idle.

Again, that's in stock form. Boost is very flexible. You can adjust fuel, boost, and ignition curves to compensate for some of that. Besides, my own stroker doesn't REALLY come alive til I'm above 3200rpm.

[mnkyboy]

No matter how you tune it a high strung 2.0l is not going to be a great truck engine.

 

It might be cool for a street only MJ but for one used as a truck or wheeler IMO I would take even the 2.5l over a 3s.

[benjy_26]

Horses for courses, I guess. Not all of us use our trucks the same way, so one guys "cool mod" is just ruining a truck for the next guy. I'm sure a turbo 4 would kind of suck for rock crawling. Take it into the dunes, though....

[johnj92131]

Pantex?  

 

http://www.pantex.com/mission/Pages/default.aspx

 

 

 
 
I'm in a top secret, underground, government installation.... J/K I'm i El Paso.
 

[benjy_26]

Lol nah... My job is much more pedestrian. I was juat being fascetious, though the desert around EP DOES look like the scenes from sci fi movies...

[Zebvance]

So I guess for a gm v6 might be the best bet for a good swap and not dealing with the head ach of a v8. Do you have to do any firewall modifications with the Buick 3.8 or the vortec 4.3.

[johnj92131]

So I guess for a gm v6 might be the best bet for a good swap and not dealing with the head ach of a v8. Do you have to do any firewall modifications with the Buick 3.8 or the vortec 4.3.

 

These are short engines, so length should not be an issue.  Now, being V engines, the width might be where your problems come in.  Also, the Buick V6 should be lighter than the Chevy V6.  And don't forget there was a 4.1 version block of the Buick V6.  Eary 80's  Also a number of books published on the Buick V6 power upgrades.  Not sure if you can get any aluminum Chevy V6 blocks or heads.  That would be nice.  As would a T5/6 trans from a Camaro.

[benjy_26]

I'd say Byoooik! Cuz boost....

[carnuck]

something totally new. (not yet available, but interesting setup blending rotary and piston technology)

 

http://pixelbark.com/13045/how-the-duke-engines-increases-the-efficiency-of-the-internal-combustion-engine

[gogmorgo]

Don't really see the Duke engine being all that reliable. Too many complex parts moving in too many directions. But what do I know.

[dasbulliwagen]

A lot of modern AC compressors are built on that design, or something similar. I never thought or wondered if something like that would make a good gas engine, but looks pretty cool. makes me wonder too if it would be possible to control valve timing like most modern variable valve timing systems on conventional engines.

[Tactical Bacon]

A rotard powered MJ would be cool for the unique factor, but that would be about it. Ever ride in an RX7? Don't make any power without a turbo and the power doesn't hit until the last 2-3k rpm. Also, torquey? When you said that, I about lost it haha. It has a very flat torque curve, sure, but it's down there really low, numberwise. If you want to make it a street screamer (and you don't mind ruptured eardrums) I say throw a 3 rotor in it, boost, and enjoy the stares. If you want to wheel it with a rotary, well, I'll keep my mouth shut since I don't feel like getting banned.

[BeenJaminJames]

But unless your goal is to be eccentric why would you?

:teehee: :rotf: :rotfl2: :laughin: :clapping:  Very punny!

 

Having rebuilt, daily driven, and modified several various rx7's I can definitely say you do not want a rotary in any vehicle that will serve offroad or towing use.  For a daily driver they can work well... keyword "can".  Rotaries get a bad rap for being unreliable, I could get on my soap box about how 99% of those issues are derived from a combination of poor decision making at Mazda and owner carelessness/ignorance, but I'll save you the grief for now.  They're actually some of the most bulletproof reliable engines ever made... but under a totally different set of circumstances.  For turning 12k rpm on 30psi of boost for an entire 24 hour endurance race, nothing else really compares.  As far as daily driver, hundreds of thousands of miles, turn-the-key-and-it-starts reliability, they're a bit below average due to higher maintenance.  Yes I've got an 84 rex in my backyard that's got 320k miles on the clock and still barks second without having ever been rebuilt.  It's also been loved it's entire life and owned by people who have been very religious about maintenance.  As far as torque?  I once put an eaton blower on a 13b and measured 369rwtq... at 5400rpm.  It took about 2500rpm to get over 100rwtq.  Need I say more?

[benjy_26]

Let's keep this going! I like it when people think outside the box. Some great ideas can come that way. What other non traditional enfines would you throw in a Manche? How about a Mazda Miller Cycle engine out of a Millenia? How about the V6 VTEC Honda engine out of the Accord? The Ridgeline won a few off road races sporting it. Maybe a V8 out of the old Infinity Q45?

[BeenJaminJames]

Let's keep this going! I like it when people think outside the box. Some great ideas can come that way. What other non traditional enfines would you throw in a Manche? How about a Mazda Miller Cycle engine out of a Millenia? How about the V6 VTEC Honda engine out of the Accord? The Ridgeline won a few off road races sporting it. Maybe a V8 out of the old Infinity Q45?

 

Creativity is the spice of life!  A rotary powered 2WD MJ would sure make a sweet and very unique autocross/sporty street truck!  I would DEFINITELY second the motion for doing a nissan VH45DE swap!  Aluminum block, dohc heads, 6 bolt mains, better port angles and chamber design than the revered toyota 1UZ, flatter powerband than the 1UZ, several good transmission options... it's probably my all time favorite v8 engine.  Oh, and if that's not enough, they take very well to turbo- and supercharging. :banana:   They're every bit as good as any LSx platform engine.

 

[Edit]  ...And from what I've seen they tend to run a bit cooler than the LSx platform motors for some reason.  Go look at the front of a 240sx drift car with a turbo LS1, keeping in mind that it spends most of it's time travelling sideways, then look at the front of your jeep and tell me about cooling problems ;)

[kazam]

In case it has not been mentioned:  whatever engine you have installed: if you can boost the compression safely

then that should yield more power. 

Examples of How to Boost compression include having the head and or block milled,

adding alternately shaped pistons (domed, etc.), ______(maybe something else)________;

valve clearance has to be correctly computed/measured so that the parts do not clash.

  I met someone who had their clearance down to a nominal .030" (between piston and valve).

 

Just a thought; I would like to rebuild the stock I-4 in the '87 MJ I have (for fun if nothing else) and see how to improve that engine.

 

The 4.0 H.O. is great and does get 26 m.p.g. depending on driving style, etc.  More power could be fun... .  It sounds great.

[benjy_26]

I do love the Jeep 2.5, but I don't think it's capable of high performance in the traditional sense. I think that with the proper cam profile, intake and exhaust, and a small, high spooling turbo, you'd have an economical, responsive engine that would out-pull a lot of higher displacement V6's and V8's.

[BeenJaminJames]

Not all engines can see a worthwhile benefit from increased compression.  In many cases they can, and the 4.0 is most certainly one of those engines.  Take for example the early Nissan KA24DE.  With a polished head, mild intake cam, tri-y header, tune, and a few other bits and bobs, it's capable of around 160-165rwhp with a manual trans, at the stock 9.0:1cr.  Using pistons from the sohc variant, it's possible to increase compression to 11.1:1.  How much power do you think can be massaged from that?  Dozens and dozens of people have tried it, yet there are no known and documented cases of anyone getting more than 170rwhp out of a high compression ka24de, even with extensive headwork and itb's.  The same is true with several other engines that have large efficient heads.  The more restrictive your cylinder head, the greater the benefit you will see from increased compression.  Remember high compression makes more power primarily because it is capable of generating higher vacuum, therefore drawing more air to fill the cylinders.  A restrictive 4.0 head will see considerable gains from high compression; a polished miata 1.8 head will see such small gains you won't notice the difference.  In cases like this it is preferable to go the other direction, lower compression, and run forced induction.  Keep this in mind when considering raising compression, depending on your engine you may just be spitting into the wind....